Senior Mechanical Engineer

Location: Either Bristol or Warrington, Cheshire

Compensation: Competitive Salary + Benefits

Role Type: Full time / Permanent

Shape the Future of UK Defence Infrastructure

At Cavendish Nuclear we’re working to create a safe and secure world, together, and if you join us, you can play your part as a Senior Mechanical Engineer, at one of our key locations: Bristol or Warrington (Cheshire).

The role

As a Senior Mechanical Engineer, you’ll have a role that’s out of the ordinary. This role will contribute to a high-impact public sector Defence Nuclear infrastructure initiative focused on enhancing operational resilience and sustainability across critical systems. The project involves complex mechanical systems integration, requiring innovative engineering solutions within a multidisciplinary team.

Day-to-day, you’ll lead the delivery of complex mechanical engineering tasks, applying deep technical expertise to solve challenging problems, produce and review high-quality documentation, and guide junior engineers, while collaborating across disciplines to ensure project milestones are met with precision and integrity.

• Foster collaboration across engineering and cross-functional teams to ensure cohesive project delivery and technical alignment.
• Build and maintain strong relationships with customers, providing clear communication and technical insight to support project progress and business development.
• Apply relevant procedures, codes, and standards rigorously to all engineering activities, ensuring compliance and technical excellence.
• Lead the production and review of engineering outputs—including calculations, drawings, models, and reports—while maintaining design integrity throughout the lifecycle.
• Identify and manage project risks, contribute to safety assessments, and support continuous improvement through technical evaluations and process enhancements.

This is a full-time, permanent position (37 hours per week) and provides hybrid working arrangements with three days in the office, based at one of our key locations: Bristol or Warrington.

Essential experience of the Senior Mechanical Engineer

• Proven experience delivering engineering activities across the full project lifecycle, from concept design through to implementation.
• Demonstrated ability to work effectively within multidisciplinary teams, contributing to complex technical solutions and project outcomes.
• Strong track record of producing and reviewing detailed engineering documentation, including calculations, drawings, and technical reports.
• Excellent communication skills with the ability to engage confidently with stakeholders and customers to resolve technical and delivery challenges.

Qualifications for the Senior Mechanical Engineer

• Engineering degree (or equivalent qualification) in relevant engineering discipline, with significant demonstrable experience.

Security Clearance

The successful candidate must be able to achieve and maintain Standard (BPSS) / Security Check (SC) security clearance for this role.

What we offer

• Generous holiday allowance
• Matched contribution pension scheme, with life assurance
• Access to a Digital GP, annual health check, and nutritional consultations through Aviva DigiCare+
• Employee share scheme
• Employee shopping savings portal
• Payment of Professional Fees
• Reservists in the armed forces receive 10-days special paid leave
• Holiday Trading is a benefit that allows UK Cavendish employees to buy additional leave or to sell up to one working week of annual leave from their annual entitlement.
• ‘Be Kind Day’ enables employees to take one working day's paid leave a year (or equivalent hours) to undertake volunteering work with their chosen organisation or registered charity
• Excellent development opportunities and benefits package including an employee assistance programme supporting physical, mental and financial wellbeing.

Company

We’re Cavendish Nuclear — a team of c5,000 specialists and a core part of Babcock International Group. Here, you’ll be part of something bigger. Across clean energy, defence, and civil decommissioning, your work will contribute to projects that are critical to energy security and national protection. Together, we’re shaping a future that lasts — not only through the impact we make, but through meaningful careers that respect your work-life balance. Join us and discover how far we can go, together.

We are a disability confident committed employer. If you have a disability or need any reasonable adjustments during the application and selection stages, please email with the subject header ‘Reasonable adjustments requirement’. We’re committed to building an inclusive culture where everyone’s free to thrive. We are happy to talk about flexible working – please ask about alternative patterns of work at interview.